Irradiating an object which is situated in or on a body, for example a tumor, with a treatment beam is known in medical applications. The treatment beam usually exhibits energies in the mega-electron volt (MeV) range, wherein planing the irradiation such that organs at risk (OAR) are not exposed to the treatment beam or are exposed as little as possible is known.
Recently, development has moved towards verifying the location of the object relative to the plan in real time during irradiation and guiding the treatment beam and/or switching it on or off when the object is situated in and/or departs from the beam path of the treatment beam. X-ray devices, the position of which relative to the treatment beam generator is known and invariable, are usually used for determining the location of the object during irradiation. The treatment beam generator and the x-ray device are for example arranged on the same support, which can be positioned relative to the body.